Fix parsing position cursor report escape sequences (#783)

The format should be:

    Cursor position report (CPR): Answer is ESC [ y ; x R, where x,y is the cursor location.

But if "R" will goes before ";", then it will panic:

    > thread '<unnamed>' panicked at '`at` split index (is 53) should be <= len (is 31)', library/alloc/src/vec/mod.rs:2110:13
    stack backtrace:
       0:         0x2978e6ea - std::backtrace_rs::backtrace::libunwind::trace::ha9053a9a07ca49cb
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
       1:         0x2978e6ea - std::backtrace_rs::backtrace::trace_unsynchronized::h9c2852a457ad564e
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
       2:         0x2978e6ea - std::sys_common::backtrace::_print_fmt::h457936fbfaa0070f
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/sys_common/backtrace.rs:65:5
       3:         0x2978e6ea - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h5779d7bf7f70cb0c
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/sys_common/backtrace.rs:44:22
       4:         0x297f1dae - core::fmt::write::h5a4baaff1bcd3eb5
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/core/src/fmt/mod.rs:1232:17
       5:         0x29781695 - std::io::Write::write_fmt::h4bc1f301cb9e9cce
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/io/mod.rs:1684:15
       6:         0x2978e4b5 - std::sys_common::backtrace::_print::h5fcdc36060f177e8
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/sys_common/backtrace.rs:47:5
       7:         0x2978e4b5 - std::sys_common::backtrace::print::h54ca9458b876c8bf
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/sys_common/backtrace.rs:34:9
       8:         0x2979122f - std::panicking::default_hook::{{closure}}::hbe471161c7664ed6
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:271:22
       9:         0x29790f6b - std::panicking::default_hook::ha3500da57aa4ac4f
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:290:9
      10:         0x297918e8 - std::panicking::rust_panic_with_hook::h50c09d000dc561d2
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:692:13
      11:         0x297917e9 - std::panicking::begin_panic_handler::{{closure}}::h9e2b2176e00e0d9c
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:583:13
      12:         0x2978eb56 - std::sys_common::backtrace::__rust_end_short_backtrace::h5739b8e512c09d02
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/sys_common/backtrace.rs:150:18
      13:         0x297914f2 - rust_begin_unwind
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:579:5
      14:         0x297ee103 - core::panicking::panic_fmt::hf33a1475b4dc5c3e
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/core/src/panicking.rs:64:14
      15:         0x297e26e6 - alloc::vec::Vec<T,A>::split_off::assert_failed::h5d4cf9fcf561634c
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/alloc/src/vec/mod.rs:2110:13
      16:         0x301f7415 - alloc::vec::Vec<T,A>::split_off::ha953b379fad89c1d
                                   at /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/alloc/src/vec/mod.rs:2114:13
      17:         0x302039ee - tuikit::input::KeyBoard::parse_cursor_report::h8a29b19f3df8e0ff

Author: azat

skim-tuikit/src/input.rs

@@ -438,6 +438,7 @@ impl KeyBoard {
         }
     }
 
+    // Cursor position report (CPR): Answer is ESC [ y ; x R, where x,y is the cursor location.
     fn parse_cursor_report(&mut self) -> Result<Key> {
         self.read_unread_bytes();
         let pos_semi = self.byte_buf.iter().position(|&b| b == b';');
@@ -447,21 +448,24 @@ impl KeyBoard {
             let pos_semi = pos_semi.unwrap();
             let pos_r = pos_r.unwrap();
 
-            let remain = self.byte_buf.split_off(pos_r + 1);
-            let mut col_str = self.byte_buf.split_off(pos_semi + 1);
-            let mut row_str = std::mem::replace(&mut self.byte_buf, remain);
+            if pos_r > pos_semi {
+                let remain = self.byte_buf.split_off(pos_r + 1);
+                let mut col_str = self.byte_buf.split_off(pos_semi + 1);
+                let mut row_str = std::mem::replace(&mut self.byte_buf, remain);
 
-            row_str.pop(); // remove the ';' character
-            col_str.pop(); // remove the 'R' character
-            let row = String::from_utf8(row_str)?;
-            let col = String::from_utf8(col_str)?;
+                row_str.pop(); // remove the ';' character
+                col_str.pop(); // remove the 'R' character
+                let row = String::from_utf8(row_str)?;
+                let col = String::from_utf8(col_str)?;
 
-            let row_num = row.parse::<u16>()?;
-            let col_num = col.parse::<u16>()?;
-            Ok(CursorPos(row_num - 1, col_num - 1))
-        } else {
-            Err(TuikitError::NoCursorReportResponse)
+                let row_num = row.parse::<u16>()?;
+                let col_num = col.parse::<u16>()?;
+
+                return Ok(CursorPos(row_num - 1, col_num - 1));
+            }
         }
+
+        return Err(TuikitError::NoCursorReportResponse);
     }
 
     fn extended_escape(&mut self, seq2: u8) -> Result<Key> {